How do I create a combobox (drop-down box) with several set strings?

Use the <a href="/Documentation:OCLOperators_Sequence" title="Documentation:OCLOperators Sequence" data-bs-title="Documentation:OCLOperators_Sequence">OCLOperators Sequence</a> to create a collection of strings that are used as a <a href="/Documentation:Tuple" title="Documentation:Tuple" data-bs-title="Documentation:Tuple">tuple</a> in a combo box.

<a href="/File:Combobox_with_strings.png" class="image" data-bs-title="File:Combobox_with_strings.png" data-bs-filetimestamp="20210211095810"><img alt="Combobox with strings.png" src="/images/3/39/Combobox_with_strings.png" decoding="async" width="476" height="150" class="thumbimage" /></a>

<a href="/File:Combobox_with_strings.png" class="internal" title="Enlarge"></a>

In the image above, the "OrderColumnName" references a string variable in the ViewModel which changes when the user selects an option.